Heretofore, in case where one could not control stool or urine excretion by own intention, or in case where one has a digestive system or urinary system disorder, the intestinal tract or urinary duct is led out to the body surface by surgical operation and a stoma is formed on the body surface. When a stoma is formed, in general, an ostomy pouch is fitted to the stoma for temporarily collecting excrement from the stoma.
In case where one has a body opening or wound in the body surface owing to any other disease, it is known to fit a drainage pouch to the opening or wound for disposing of excrement discharged by drainage or the like.
Many improvements have been made repeatedly on ostomy pouches and drainage pouches (hereinafter these may be simply referred to as “pouch for a body waste collector”), and essential problems in practical use are being solved in points of smell prevention and wearability improvement.
However, current pouches for a body waste collector still have serious problems on disposal of excrement.
Specifically, when excrement is collected in a pouch, the pouch must be disposed of after excrement therein is disposed of. For disposing of excrement, it must be drained off or must be scraped out. The operation is troublesome, and is an unpleasant operation owing to the bad smell of excrement and inevitable stool adhesion. In addition, the operation requires some space, and there may be a risk that the pouch may be damaged during the operation causing excrement to leak out of the pouch.
Accordingly, as a method for disposing of excrement collected in a pouch, there are disclosed a lot of techniques of flushing away the pouch for a body waste collector along with excrement therein in a flush toilet (for example, see Patent Reference 1).    Patent Reference 1: JP-T 2007-508905
However, for flushing away a pouch in a toilet, the pouch must have mechanical strengths to such a degree that it does not leak excrement for a period of time even while it keeps excrement collected therein (or that is, even while it is in wet), and on the other hand, when it is disposed of in a flush toilet, it must be disintegrated and decomposed so as not to clog up a septic tank and others. Accordingly, there is a problem that it is difficult to achieve both water resistance and water-degradability.